Case changing mechanism for typewriters



1954 5. F. TURNER CASE CHANGING MECHANISM FOR TYPEWRITERS Filed Oct. 21, 1952 INVENTOR. Gary FT Turner 77257714114 14 flWz rum United States Patent() 4 CASE: Fon- GaryFmnkrTnmenzBoscobel; win. Application Qciobenfll, 1952,',SerialrNo.- 315,869

servation that the conventional construction is such: as to require that'the hardest work done by the little :fingers', withthe lightest" world beingdone-by therthumbs of the hands. The thumbs, of" course, are much stronger than the little fingers, a-nd it isdhereforethe main object of'the present invention to 1 provide an 1 improved case changing meansior typewriterswhich will be particularly arranged for -actuation by-' t lie thumbs, rathen-than b'y'the small fingers-oi thehands.

It is another irnportant'obiec't of thepresent invention to-provide'a case changing mechanism of the type statedwhich will notonly' be designed-for actuation by the thumbs, .but 'will also be so designed: as to" permit a single-case-cliangebarto beused; both for: elevating the platencradl'e'and for holdinggsthe'platen cradle releasably 1'i11its--elevateclposition;- In conventional typewriter constructionsyseparate "keys mustbeprovided, namely, a shift key and ashift lock key, one of the keys being adapted only'for elevating the cradle; andthe other key, namely, the shift lockkey, being both-for 'elevatingand releasably locking; the cradle in -its elevated position:

Other objects-will appear from the following description, the claims "appended thereto, and fromthe' annexed drawing, inwvhich-likereference characters designate like parts throughout'th'e several views; and wherein Figure :1 is a' perspective view oftlie' main frame of 'a typewriter; thepla'tencradle thereof, andthe case chang ing means constituting the present" invention, aportion of said'main frame being broken away; v

Figure 2 is an-enlarged,detailsectionalviewtaken substantiallyontline 2'-2 of" Figure -l the case-changebar being shown in a the depressed position thereof, as" it ap-' pears whentheplaten-rcradlezis not'to be locked in elevated position;

Figure. 3 is .a transverse-sectional view; ,also' taken on line 2. .-2but.1ooking,in the opposite. direction, the; casechange ban being ,shown in its cradle-lockingposition;

Eigure 4 .is a fragmentary-perspective:view of the/case bar; and .of oneof .theelevers -.supporting--;thersame, said :bar: and lover. beingdisassembled from one another; andi Figure: 5 :-:is" a' fragmentary top: plans view of the front portion :of a typewriter, showing the =caseschahge bar; in the relation =that* it bears to -the letterkeys and space: bar of the machine.

Referring to .the, drawing in detail, the reference numeral has been applied generally to a typewriter, said typewriter havingia main frame 12. Since/the main frame 12 is ,ofconventional construction, it-will not be described imdtail'. Ittwill be understood, insthis-connectionsthat imFig'ure 1, .only' the main frame and. those -parts-that necessarily; cooperate with the present invention haverh'een illustrated,'.for the purpose of 'clarityi Mounted upon the rear portion of the main frame 12 is a platen cradle 14 on which is supported the conventional platen 16, said platen cradle 14 being mounted for 2,693,265 i'atented Nov. 2,1954

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uprrandr down: inovemcntzto upper: andlower: case" posh trons.

The typewriterris: equipped with =therusual keys 18 and sparezbarr20i- Theapartssso fa-r illustrated and: described are wholly conventional, and do: not; per 'se, .constitute part of the present invention.-..

The: invention: has i beendesignated generally by: the reference 1 numeral: 24, said invention comprising a-casm changing means adapted tube operatedi'by wuserfor elevating; andloweringgthe. platen cradle: 14'.

Inaccordance with the present invention,.a pivot-pin 26 is provided, said pin extending between the respective sidtrwalls-ofrthc main frame-12, at-a location intermediate theirontiandtbackof the typewriter. At its opposite ends,

, the pinZG'isengagedJn'aligned openingsformed inrsaid side walls, saidpin being also extended'throughopenings formed in iapair of parallel levers 28.

The. levers 28, as. shown in Figure 1, extend -longitudi= nallytof;therespectiveside wallsof themain frame, said levers; being; spaced; inwardly. a 1 short distance fronr said side walls The-leverss28 are thus pivoted-about 'a com mon axis represented by the pin 26, said levers swinging in parallehvertical planes, Aswill benoted'from 'Figure 1, the pivottaxisrof-the levers 28. is disposed intermediate the oppositeends-of thelevers, .but'is closer to thefront ends -ofi the levers-,thatris, those ends disposed adjacent the: front of the typewriter, than :it is to the. backends oflthe levers.-

Formed in the back" ends of 1 thelevers28lare openings receiving connecting pins- 30,. said pins' 30 extending through :the lower ends of substantially. vertical, parallel links 32, Thelinks Slextendupwardly along-the respecfive-sidewalls of the mainframe; and at th'eirupper. ends are connectedto. theopposite ends of the platen cradle'14:

It will thus beLseen thatif theirontends of theulevers 28. are. depressedatheirear ends thereofIWill rise, shifting the links 32:' upwardly in the..-direction.of their:length's; thus to. elevatetheplat'en cradle. Normally, theplaten cradle tends. .to. gravitate to 1 a lower position, and will Lso gravitatewhena positive .force is-vnotrapplied to thezfront ends. of! the. leversotendingdo. depress the same.

Formed upomeach 1ever;28,.at.the. fr'ontend ofthe lever, is. a short, upstandingextension 34-(Figure4);.the extensions-340i. the levers having openings 3'6I The openings 36. register. with openings 38" provided" in dependingextensionsh lil of. a t case-change bar 41...

Pivot pins 42 extend lthrough the: registeringopenings 3.6, 38,. thus .to mount the. case=change 2 bar. 41 upon the levers. 28 for: pivotall movement about ..an...axis. extending 1n parallelism with thealongitudinal center. line of. the caserchange bar: s

In. this way, thecase-change bar is amounted to. rock transversely uponth'e .front ends of. the levers- 28';.be= tween a position sh'ownin. Figure. 2;..and a position shown in "Figure: 31

As. will; besnoted from: Figures. 1 and 5, the; case= change .bartisi elongated, extending substantially from side -to.side'of the typewriter, in. .closely spaced, parallel relation .to. thecoaventional. Spacebar 20 ofLthe machine; A'ccQrdingIy, .the. case-change, bar 41Zis disposed for do pression by the thumbs, rather thanby thesmallfingers,

of a users hand, and'when the-'caseechange bar. is

depressed, it. will be. efiective to cause elevation vof the platen cradle 14..

Secured'to-the underside of the. case-change bar 41, adjacent the opposite. endssthereofl'are apertured. lugs 44, andwhooked at th'eir. upper; ends in the lugs 44 aresprings.-46.- Thesprings46-are hookedlattheir lower ends in the. upstanding'zextensions 34 of the levers/28; saidisprings being-of the: coiled,. contractile type. Thus, the springs-will tend, when the case-change bar is rocked to the posit-ion thereotshowninFig'ure 3, to resist-said movement of the .case-changebar in this direction, andt-the springs-- will thus-provide means for norm-ally 'holding the: case-change: bar in! the: position thereof ShOWBsiH Figure-:2},

Formed. upon the: lowerrendf of cach -extension: 40' of the case-change bar is a laterally projected lug 48, said lug 48 extending into the path of the upstanding extension 34 of its associated lever 28. The lug 48 limits swinging movement of the case-change bar from the position thereof shown in Figure 3 to the position thereof shown in Figure l, the lug 48 engaging the extension 34 to prevent the return spring 46 from pulling the casechange bar 41-beyond the normal, horizontal position thereof.

Immediately above the lug 48 of each extension 40 is a notch 50, said notch 50 complementing, and being adapted to receive, a detent 52 provided upon a bracket 54. The brackets 54 areprojected inwardly of the main frame, from the front wall of the typewriter, and are fixedly secured tosaid front wall. Normally, the detents 52 do not interfere with depression of the case-change bar 41, said detents being disposed out of the path of downward movement of the extensions 40 of the case-change bar,

when said extensions 40 are disposed vertically as in Figure 2.

By reason of this arrangement, one is permitted to depress the case-change bar 41 for elevating the platen cradle momentarily, without locking the platen cradle in its elevated position.

If, however, it is desired to lock the platen cradle in its elevated position, the user, after depressing the casechange bar 41, exerts a lateral pressure upon said bar, tending to rock the bar in the direction of the user, that is, in the direction of the low front wall of the main frame.

When this is done, the case-change bar will be rocked transversely as shown in Figure 3, with the lower end of each extension 40 swinging toward the detent 52 adjacent thereto. As a result, the respective detents 52 will engage in the notches 50 of the depending extensions 40 of the case-change bar, thus to hold the case-change bar in its depressed position and thereby lock the platen cradle 14 in its elevated position.

At such time as the cradle is to be unlocked, it is necessary only that a lateral pressure be exerted upon the case-change bar 41, in the direction of the platen cradle. This causes the detents 52 to be disengaged from their associated notches 50, thus permitting the springs 46 to contract, in a manner effective to return the case-change bar 41 to its normal position shown in Figure 2. As a result, the case-change bar 41 is permitted to rise, with the platen cradle dropping to its lower position.

It is seen from the above that the construction of the invention is such as to permit movement of the platen cradle between its upper and lower positions, responsive to thumb pressure exerted by the user, rather than by finger pressure exerted by the little fingers of the users hands. Further, the construction is such as to embody in the bar 41 not only a thumb-receiving key for elevating the platen cradle, but also a combination shift key and shift lock key, this construction being distinguished from that of conventional typewriters, wherein it is usual to provide a shift key separate from a shift lock key.

It is believed apparent that the invention is not necessarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and de- 1 scribed, since such construction is only intended to be illustrative of the principles of operation and the means presently devised to carry out said principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope of the appended claims.

What is claimed is:

1. In a case-changing mechanism for a typewriter, the combination with a main frame and with a platen cradle mounted thereon for up and down movement between upper and lower case positions, of a pair of levers arranged longitudinally of opposite sides of the frame and mounted thereon to pivot about a common, horizontal axis; a case-change bar pivotally connected at its opposite ends to one end of the respective levers and arranged for depression by a user to rock the levers about said pivot axis thereof, the other ends of the levers having a connection to the platen cradle for elevating the cradle responsive to depression of said bar by a user; and detent means carried by the main frame and arranged to releasably engage said bar in the depressed position thereof, to hold the cradle in its elevated position, said detent means being disposed to engage the bar on pivotal movement of the bar in one direction upon its associated levers while in said depressed positlon.

2. In a case-changing mechanism for a typewriter, the combination with a main frame and with a platen cradle mounted thereon for up and down movement between upper and lower case positions, of a pair of levers arranged longitudinally of opposite sides of the frame and mounted thereon topivot about a common, horizontal axis; a case-change bar pivotally connected at its opposite ends to one end of the respective levers and arranged for depression by a user to rock the levers about said pivot axis thereof; links extending upwardly along the opposite sides of the frame and pivotally connected at their opposite ends to the other ends of the levers and the cradle respectively, for elevating the cradle responsive to depression of said bar by a user; and detent means carried by said main frame and arranged to. releasably engage said bar in the depressed position thereof, to hold the. cradle in its. elevated position, said detent means being disposed to engage the bar on pivotal movement of the bar in one direction upon its associated levers while in said depressed position.

3. In a case-changing mechanism for a typewriter, the combination with a main frame and with a platen cradle mounted thereon for up and down movement between upper and lower case positions, of a pair of levers arranged longitudinally of opposite sides of the frame and mounted thereon to pivot about a common, horizontal axis; an elongated case-change bar extending substantially from side to side of the main frame and connected at its opposite ends to one end of the respective levers For pivoting on the levers about an axis paralleling the ongitudinal center line of the bar, said bar being arranged for depression by a user to rock the levers about said pivot axis of the levers; links extending upwardly along the opposite sides of the frame and pivotally connected at their opposite ends to the other ends of the levers and to the cradle, respectively, for elevating the cradle responsive to depression of said bar by a user; and detent means carried by the main frame and arranged to releasably engage said bar in the depressed position thereof, to hold the cradle in its elevated position, said detent means being disposed to engage the bar on pivotal movement of the bar in one direction upon its associated levers while in its depressed position.

4. In a case-changing mechanism for a typewriter, the combination with a main frame and with a platen cradle mounted thereon for up and down movement between upper and lower case positions, of a pair of levers arranged longitudinally of opposite sides of the frame and mounted thereon to pivot about a common, horizontal axis; an elongated case-change bar extending substantially from side to side of the main frame and connected atits opposite ends to one end of the respective levers for pivoting on the levers about an axis paralleling the longitudinal center line of the bar, said bar being arranged for depression by a user to rock the levers about said pivot axis of the levers; links extending upwardly along the opposite sides of the frame and pivotally connected at their opposite ends to the other ends of the levers and to the cradle, respectively, for elevating the cradle responsive to depression of said bar by a user;

' stationary detents carried by the main frame, said bar having depending extensions formed with detent-receiving notches, said notches and detents providing means to hold the cradle in its elevated position, said detents being disposed to engage in the notches on pivotal movement of the bar in one direction upon its associated levers while in its depressed position; and springs connected between the extensions and levers and tensioned t o normally bias the bar out of its detent-engaged pos1t1on.

References Cited in the file of this patent UNITED STATES PATENTS Number 

